2006/12/01 by E. Kennedy, M. O'Donovan, J. P. Murphy +2
paper · doi:10.1111/j.1365-2494.2006.00544.x
Abstract The objective of this study was to investigate the effects of an early (February; F) or delayed (April; A) primary spring grazing date and two stocking rates, high (H) and medium (M), on the grazing management, dry matter (DM) intake of grass herbage and milk production of spring‐calving dairy cows grazing a perennial ryegrass sward in the subsequent summer. Sixty‐four Holstein‐Friesian dairy cows (mean of 58 d in milk) were assigned to one of four grazing treatments ( n = 16) which were imposed from 12 April to 3 July 2004. Cows on the early spring‐grazing treatment were grazed at 5·5 cows ha −1 (treatment FH) and 4·5 cows ha −1 (treatment FM) while cows on the late‐grazing treatment were grazed at 6·4 cows ha −1 (treatment AH) and 5·5 cows ha −1 (treatment AM). The organic matter digestibility and crude protein concentration of the grass herbage were higher on the early‐grazing treatment than on the late‐grazing treatment. The cows on the FM treatment had significantly ( P P P −1 ; FM) resulted in the highest DM intake of grass herbage and milk production.